
科学技术与工程

中国技术经济学会
新疆油田火驱区块采油井D级杆腐蚀失效分析
李杰 , 李屹洋 , 苏日古 , 余成秀 , 丁坤 , 陈登亚 , 曾德智
科学技术与工程 ›› 2025, Vol. 25 ›› Issue (3) :992-998
新疆油田火驱区块采油井D级杆腐蚀失效分析
Corrosion Failure Analysis of D-class Rod in a Fire Drive Production Well in Xinjiang Oilfield
新疆油田某火驱采油井抽油杆腐蚀严重,表面有多处腐蚀坑。为找出抽油杆腐蚀失效原因,对失效抽油杆进行金相组织和理化性能测试分析,利用扫描电子显微镜、能谱仪、X射线衍射分析等进行腐蚀特征分析,结合抽油杆服役工况找出失效原因。结果表明:D级抽油杆的化学成分、金相组织、夹杂物等均符合抽油杆标准要求,抽油杆服役仅1年8个月直径从19 mm降为16 mm,平均腐蚀速率为1.796 mm/a,表面最大腐蚀坑深度为2.1 mm。抽油杆表面附着物主要为FeCO3、FeS、CaCO3,判断抽油杆发生了CO2/H2S腐蚀、高矿化度采出水引起的垢下腐蚀,同时,采出液中大量的Cl -促进了点蚀坑的发展。建议对温度低于50 ℃、pH介于6 ~ 8、地层水属于高钙、高氯的采油井注入缓蚀阻垢剂对D级抽油杆进行防护,延长抽油杆使用寿命。
The rod of a fire drive production well in Xinjiang oilfield is seriously corroded, and there are many corrosion pits on the surface. In order to find out the cause of rod corrosion failure, the metallographic structure and physical and chemical properties of the failed rod were tested and analyzed, and the corrosion characteristics were analyzed by scanning electron microscope, energy spectrometer and X-ray diffraction analysis, and the failure causes were found out combined with the service conditions of the rod. The results show that the chemical composition, metalloid structure and inclusions of the D-class rod meet the standard requirements of the rod. The rod has only been in service for 1 year and 8 months and its diameter has decreased from 19 mm to 16 mm, the average corrosion rate is 1.796 mm/a, and the maximum surface corrosion pit depth is 2.1 mm. The surface of the rod is mainly attached with FeCO3, FeS and CaCO3. It is judged that the rod is corroded by CO2/H2S and underscale corrosion caused by high salinity produced water. At the same time, a large amount of Cl - in the produced liquid promotes the development of pitting pits. It is recommended to inject corrosion and scale inhibitor into production wells with temperature lower than 50 ℃, pH value between 6 and 8, and formation water belonging to high calcium and high chlorine to protect the D-class rod and extend the service life of the rod.
fire flooding / the rod / corrosion / scale formation / cause of failure
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